Snailfish filmed at a depth of 8,336 m in the Ogasawara Trench certified as the "World's Deepest Fish"

Tokyo University of Marine Science and Technology (President: Toshio Iseki) announced on April 4, 2023, that a snailfish filmed at a depth of 8,336 meters during a scientific survey of four hadal trenches around Japan has been recognized by Guinness World Records^® as the deepest fish ever found in the world. The deep‐sea survey was conducted by Dr. Hiroshi Kitazato at the Department of Marine Environmental Science of Tokyo University of Marine Science and Technology in collaboration with Professor Alan Jamieson at The Oceans Institute and the School of Biological Sciences of the University of Western Australia and Director of the Minderoo‐UWA Deep‐Sea Research Centre.

On the same day, an official certificate award ceremony was held at Shinagawa Campus of Tokyo University of Marine Science and Technology (Konan, Minato‐ku, Tokyo). The deep‐sea survey, conducted from August 5 to September 19, 2022, was part of the 'Ring of Fire 2022 Japan Expedition' campaign that was carried out aboard the deep‐sea survey vessel (DSSV) Pressure Drop. This campaign involved researchers from several organizations and countries, including the Japan Agency for Marine‐Earth Science and Technology, Nagoya University, Niigata University, The University of Tokyo, University of Southern Denmark and other research institutes, with Jamieson as the principal investigator and Kitazato as the co‐principal researcher on the Japan side.

The officially certified snailfish was captured in a video on August 15 in the Ogasawara Trench. Details of the fish, which was not physically caught, are unknown except for the fact that it is a snailfish in the family Liparidae of the order Scorpaeniformes. However, it is believed to be approximately 20 centimeters long. Jamieson's many years of research contributed to the discovery. The habitat limit of fish is thought to be 8,200 to 8,400 meters below sea level, beyond which the water pressure will cause changes to the three‐dimensional structure of its proteins.

At the ceremony, Kaoru Ishikawa, a representative of Guinness World Records Japan, presented the official certificate to Kitazato. He then commented, "We believe that our dive opened the door to the ultra‐deep sea. Many wonders were revealed by opening this door. Our message to everyone is that we hope that they be interested in the ultra‐deep sea and please join us in visiting it." He also said that both he and Professor Jamieson thought that it was the fish that should be honored. The detailed results of the survey will be published in a paper in the future.

Besides this, special exhibitions at the venues such as the Marine Science Museum of Tokyo University of Marine Science and Technology and the National Museum of Nature and Science are scheduled for this summer.